In general, lithium ion (Li-ion) batteries are principally used in consumer electronic devices such as lap-top computers, cell phones, cameras, camcorders and MP3 players. Li-ion batteries used in the above-mentioned devices can be made in a single electrochemical cell or multi cells in series or parallel dependent upon power consumption needs. Lap-top computer batteries usually include four to nine individual cells per pack. The cells used in these devices are typically small in capacity (<2 ampere hour (Ah) typically). Cells used in consumer electronic devices are typically of a wound electrode configuration. The structure is a long narrow sandwich having cathode layer/separator layer/anode layer/separator layer that is spiraled on a mandrel forming a “jelly roll” monolithic structure. The jelly roll can be processed in the following ways:                (1) The jelly roll may be a tight spiral wind that is subsequently placed in a cylindrical can for further processing—i.e. 18650 and 26650 standard size round cells used in lap-top computers and power-tools. Here, “18” means that the can is 18 mm in diameter, and “65” means that the can is 65 mm in height. “0” has no meaning here.        (2) The jelly roll may be a compressed flattened jelly roll that is subsequently placed in a plastic pack as is typically used in cell phone batteries, MP3 players and like sized devices.        
The wound format lends itself to the rapid construction of the electrode/separator mass and the large scale automation of the fabrication process. Typically, the electrode/separator mass can be wound in a few seconds (approximately 2). A single automated machine can construct millions of these cell structures in a typical operation over a short period of time. To date, 18650 and 26650 wound Li-ion cells are in large quantity production mode and have an electrochemical capacity often less than 4 Ah depending on cell design and the electrode material chosen. The wound cell design for large capacity power needs is not practical for a few reasons, including the processing practicality to maintain concentricity of all the wound electrodes and safety concerns due to thermal management issues when the battery is in a high rate charge or discharge mode.
While cells of less than 4 Ah capacity are typically of a wound based construction, the large capacity cells (“large format” cells) are of a stacked construction where the electrode/separator mass includes of a number of alternating layers of separator/cathode (or anode) electrode/separator/anode (or cathode) electrode with this stacking arrangement repeating a number of times (e.g., 25 to 50) to reach the desired cell capacity according to the cell design and specification.
Current processes for stacking large format cells depend on manual hand stacking or the use of a stacking machine that accommodates provisions for the automatic laying of the alternate layers of the electrode/separator mass.
The process of manual hand stacking cannot ensure the precision of the stacking process, and cannot ensure the quality of the stacking cells.
Current stacking equipment requires that each cathode and anode electrode layer must be cut to its size and shape in a separate process. Due to its thinness and propensity to acquire a static electrical charge during handling, a special machine must be provided to cut or fold the separator material (e.g., −Z fold). The electrode layers are placed onto their respective alternating layers using a pick-and-place technique whereby a single machine device (e.g., an arm) will pick-up a single electrode layer and deposit it upon the cell stack. Typically the electrode is held onto the pick-up device via a reduced air pressure (vacuum) applied at the point of contact of the device and the electrode surface. The action of picking-up and depositing an electrode upon the stack occurs over the course of a few seconds (about 2 to about 5). In the case of a typical 25 composite electrode layer cell, the stacking will take from about 2 to about 5 minutes to complete. Thus, an automated manufacturing system for a layered cell having an improved structure and a manufacturing process that simplifies and enhances assembling efficiency in a continuous process is needed.